1. Field of the Invention
The present invention relates to a socket and, particularly, to a socket best used for loosening a rusted and rotten fastener or a fastener which corners have been damaged.
2. Description of the Related Art
It is known that a fastener has a polygonal head for engagement with a driving member, with the driving member being used to drive the head of the fastener for tighten/loosening the fastener. Unfortunately, it has always been a problem to loosen a fastener which has been tightened unduly or which has become rusted and rotten. One reason is because a force that is applied to the fastener has to be very large in order to loosen it. Another reason is that the driving member would damage and wear the acute corners during the operation thereof. It is noted that each acute corner defined between two adjacent sides of the polygonal head would suffer a “collapse” problem, namely, the corner becomes arcuate and is no longer acute. Consequently, it becomes impossible to loosen the fastener from the object no matter how hard the driving member is turned.
China Pat. No. ZL 96215962.X teaches a spanner for wrenching a worn nut. The structure thereof, however, is complicated, which inflicts high cost of manufacture.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.